EP1380633B1 - Use of oily liquids to improve the oxidation stability of fuel oils - Google Patents

Description

The present invention relates to oils having improved oxidation stability containing fatty acid esters and alkylphenol resins,

With decreasing world oil reserves and the environmental impact of fossil and mineral fuel consumption, there is a growing interest in alternative energy sources based on renewable raw materials. These include, in particular, natural oils and fats of plant or animal origin. These are usually triglycerides of fatty acids with 10 to 24 carbon atoms, which have a comparable calorific value to conventional fuels, but are also classified as biodegradable and environmentally friendly.

entsprechen, in der R ein aliphatischer Rest mit 10 bis 25 Kohlenstoffatomen ist, der gesättigt oder ungesättigt sein kann.Oils obtained from animal or vegetable material are principally fabric invertebrates comprising triglycerides of monocarboxylic acids, e.g. As acids having 10 to 25 carbon atoms, and the formula

in which R is an aliphatic radical of 10 to 25 carbon atoms, which may be saturated or unsaturated.

In general, such oils contain glycerides of a number of acids, the number and variety of which varies with the source of the oil, and they may additionally

Contain phosphoglycerides. Such oils can be obtained by methods known in the art.

Due to the sometimes unsatisfactory physical properties of the triglycerides, the art has shifted to converting the naturally occurring triglycerides into fatty acid esters of lower alcohols such as methanol or ethanol.

In addition to their direct use as fuel, fatty acid alkyl esters are also used as additives for, for example, mineral oils and mineral oil distillates. In particular, fuel oils with a sulfur content reduced to less than 500 ppm have such poor friction and wear-reducing properties that so-called lubricity additives must be added to them. These are based inter alia on esters of unsaturated fatty acids with lower alcohols (biodiesel).

The oily fluids used as fuel oils and additives are mainly based on oils from natural sources such as oilseed rape, sunflowers, soya and similar oilseeds. These have a high content of unsaturated fatty acids of more than 50%, and preferably of more than 80%, which gives them acceptable rheological properties, especially in the cold.

So revealed EP-A-0635558 the use of biodiesel based on C ₁ -C ₅ -alkyl esters of saturated and unsaturated, straight-chain C ₁₂ -C ₂₂ fatty acids as lubricity improvers for gas oils with low sulfur and aromatic content.

EP-A-0935645 discloses the use of C ₁ -C ₃₀ alkylphenol resins as lubricity additives for low sulfur diesel. The examples used are C ₁₈ and C ₂₄ alkylphenol resins.

WO-99/61562 discloses blends of alkylphenol resins, nitrogen containing compounds and ethylene copolymers as refrigerants and lubricity additives for low sulfur diesel.

DE-A-10111857 discloses esters of predominantly saturated unbranched monofatty acids with mixtures of C ₁ -C ₄ monoalcohols with methylated mono- and / or dihydroxybenzenes as an additive to sulfur-free mineral diesel fuel. The hydroxybenzenes improve, inter alia, the oxidation stability of the additives.

The oily liquids based on esters of unsaturated fatty acids, which are preferred because of their rheological properties over the esters based on saturated fatty acids, can, on prolonged storage, especially at elevated temperature, harden to only partially oil-soluble products. This can lead to the formation of viscous precipitates and deposits in the storage container as well as in the additized fuel oil. Even in the engine, this can lead to deposits, in particular at the valves and injection nozzles.

In addition, the effectiveness of the agricultural production in large quantities and inexpensive available fatty acid esters based on oilseeds as lubricity additives is comparatively low. In order to achieve a sufficient effect in practice, consequently, high dosage rates of 1,000 ppm and more are required, which requires a high logistical effort.

The object of the present invention was therefore to find fuel oils and additives based on unsaturated vegetable and animal oils, which have an improved oxidation stability compared with the prior art.

Surprisingly, it has been found that combinations of esters of unsaturated fatty acids with alkylphenol-aldehyde resins have a significantly improved oxidation stability.

• A) mindestens einen Ester aus Fettsäuren, deren Kohlenstoffkettenlängen zwischen 8 und 30 Kohlenstoffatomen liegen, und einem einwertigen C₁-C₅-Alkohol, wobei mindestens 50% der Fettsäurereste mindestens eine Doppelbindung enthalten, und
• B) 0,005 bis 20 Gew.-% mindestens eines Alkylphenol-Aldehydharzes, erhältlich durch die Kondensation von
  1. (i) mindestens einem Alkylphenol mit mindestens einem C₆-C₂₄-Alkyl oder C₆-C₂₄-Alkenylrest und
  2. (ii) mindestens einem Aldehyd oder Keton,
  wobei der Kondensationsgrad zwischen 2 und 50 Alkylphenoleinheiten beträgt, in Brennstoffölen mit maximal 0,035 Gew.-% Schwefelgehalt, in einer Menge von 0,02 bis 10 Gew.-%, bezogen auf das Brennstofföl, zur Verbesserung der Oxidationsstabilität der Brennstofföle.

The invention is therefore the use of oily liquids containing

• A) at least one ester of fatty acids whose carbon chain lengths are between 8 and 30 carbon atoms and a monohydric C ₁ -C ₅ -alcohol, wherein at least 50% of the fatty acid residues contain at least one double bond, and
• B) 0.005 to 20 wt .-% of at least one alkylphenol-aldehyde resin, obtainable by the condensation of
  1. (i) at least one alkylphenol having at least one C ₆ -C ₂₄ -alkyl or C ₆ -C ₂₄ -alkenyl radical and
  2. (ii) at least one aldehyde or ketone,
  wherein the degree of condensation is between 2 and 50 alkylphenol units, in fuel oils having a maximum of 0.035% by weight of sulfur, in an amount of 0.02 to 10% by weight, based on the fuel oil, for improving the oxidation stability of the fuel oils.

The oily liquids defined above are also referred to below as additives.

Preferred fatty acids which are part of the esters A) are those having 10 to 26 C atoms, in particular 12 to 22 C atoms. The alkyl radicals or alkenyl radicals of the fatty acids consist essentially of carbon and hydrogen. However, they may carry other substituents such as hydroxy, halogen, amino or nitro groups, provided they do not affect the predominantly hydrocarbon character. The fatty acids preferably contain at least one double bond. They may contain multiple double bonds, for example 2 or 3 double bonds, and be of natural or synthetic origin. In the case of polyunsaturated carboxylic acids, their double bonds may be isolated or else conjugated. Preference is given to mixtures of two or more unsaturated fatty acids having 10 to 26 carbon atoms. In particularly preferred fatty acid mixtures, at least 75% by weight, especially at least 90% by weight, of the fatty acids contain one or more double bonds. The iodine numbers of the Fatty acids or fatty acid mixtures according to the invention are preferably above 50 g J / 100 g, more preferably between 100 and 190 g J / 100 g, in particular between 110 and 180 g J / 100 g and especially between 120 and 180 g I / 100 g fatty acid or fatty acid mixture.

Suitable unsaturated fatty acids are, for example, oil, eruca, palmitoleic, myristoleic, linoleic, linolenic, elaeosterolic, arachidonic and / or ricinoleic acid. Preference is given to fatty acid mixtures or fractions obtained according to the invention from natural fats and oils, e.g. Peanut oil, fish, linseed oil, palm oil, rapeseed oil, ricinoleic, castor oil, rapeseed oil, soybean oil, sunflower oil, Färberdistel- and tall oil fatty acid having corresponding iodine numbers.

Also suitable as constituent of the fatty acid mixtures are dicarboxylic acids, such as dimer fatty acids and alkyl- and alkenylsuccinic acids with C ₈ -C ₅₀ -alk (en) yl radicals, preferably with C ₈ -C ₄₀ -, in particular with C ₁₂ -C ₂₂ -alk (s) ylresten. The alkyl radicals can be linear or branched (oligomerized alkenes, polyisobutylene) and saturated or unsaturated. Preference is given to fractions of up to 10% by weight, in particular less than 5% by weight, based on the constituent A).

In addition, the fatty acid mixtures may contain minor amounts, i. up to 20% by weight, preferably less than 10%, in particular less than 5% and especially less than 2% of saturated fatty acids such as, for example, lauric, tridecane, myristic, pentadecane, palmitic, margarine, stearin, Contain isostearin, arachin and behenic acid.

The fatty acids can furthermore contain 1-40% by weight, especially 1-25% by weight, in particular 1-5% by weight of resin acids.

Suitable alcohols contain 1 to 5 carbon atoms. Particularly suitable alcohols are methanol and ethanol, in particular methanol.

The esters can be prepared from alcohols and fatty acids in a known manner by esterification. Preferably, the transesterification of naturally occurring fats and oils with lower alcohols and in particular with methanol, being by-produced Glycerin is formed. Preference is given to those esters which can be prepared from a fatty acid mixture.

The contained in the additive alkylphenol-aldehyde resins (B) are known in principle and, for example, in Rompp Chemie Lexikon, 9th edition, Thieme Verlag 1988-92, Volume 4, p 3351ff , described. The alkyl or alkenyl radicals of the alkylphenol have 6-24, preferably 8-22, in particular 9-18, carbon atoms. They may be linear or preferably branched, wherein the branch may contain secondary as well as tertiary structural elements. It is preferably n- and isoHexyl, n- and iso-octyl, n- and iso-nonyl, n- and iso-decyl, n- and iso-dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl and tripropenyl, tetrapropenyl, Pentapropenyl and polyisobutenyl up to C ₂₄ . The alkylphenol-aldehyde resin can also be up to 20 mol% of phenol units and / or alkylphenols with short alkyl chains such. B. butylphenol. For the alkylphenol-aldehyde resin, the same or different alkylphenols may be used.

The aldehyde in the alkylphenol-aldehyde resin has 1 to 10, preferably 1 to 4, carbon atoms and may carry further functional groups. It is preferably an aliphatic aldehyde, more preferably it is formaldehyde.

The molecular weight of the alkylphenol-aldehyde resins is preferably 350 to 10,000, in particular 400 to 5000, g / mol. This preferably corresponds to a condensation degree n of from 3 to 40, in particular from 4 to 20. The prerequisite here is that the resins are oil-soluble.

sind, worin R^A für C₆-C₂₄-Alkyl oder -Alkenyl und n für eine Zahl von 2 bis 50 steht.In a preferred embodiment of the invention, these alkylphenol-formaldehyde resins are those which are oligomers or polymers having a repeating structural unit of the formula

wherein R ^{A is} C ₆ -C ₂₄ alkyl or alkenyl and n is a number from 2 to 50.

The preparation of the alkylphenol-aldehyde resins is carried out in a known manner by basic catalysis, resulting in resol-type condensation products, or by acid catalysis to form novolac-type condensation products.

The condensates obtained according to both types are suitable for the compositions according to the invention. Preferably, the condensation is in the presence of acidic catalysts.

For the preparation of the alkylphenol-aldehyde resins, an alkylphenol having 6-24, preferably 8-22, in particular 9-18, carbon atoms per alkyl group, or mixtures thereof, and at least one aldehyde are reacted with each other, wherein about 0.5 mol per mol of alkylphenol compound. 2 mol, preferably 0.7 to 1.3 mol and in particular equimolar amounts of aldehyde are used.

Suitable alkylphenols are in particular n- and iso-hexylphenol, n- and isoctylphenol, n- and iso-nonylphenol, n- and iso-decylphenol, n- and iso-dodecylphenol, tetradecylphenol, hexadecylphenol, octadecylphenol, eicosylphenol, tripropenylphenol, tetrapropenylphenol and polyols (isobutenyl) phenol -C _24th

The alkylphenols are preferably para-substituted. The alkylphenols may carry one or more alkyl radicals. Preferably, they are substituted at most 5 mol%, in particular at most 20 mol% and especially at most 40 mol% with more than one alkyl group. Preferably carry at most 40 mol%, in particular

at most 20 mol% of the alkylphenols used in the ortho position an alkyl radical. Specifically, the alkylphenols ortho to the hydroxyl group are not substituted with tertiary alkyl groups.

The aldehyde can be a mono- or dialdehyde and carry other functional groups such as -COOH. Particularly suitable aldehydes are formaldehyde, acetaldehyde, butyraldehyde, glutaric dialdehyde and glyoxylic acid, with formaldehyde being preferred. The formaldehyde can be used in the form of paraformaldehyde or in the form of a preferably 20-40% strength by weight aqueous formalin solution. Corresponding amounts of trioxane can also be used.

The reaction of alkylphenol and aldehyde is usually carried out in the presence of alkaline catalysts, for example alkali metal hydroxides or alkylamines, or of acidic catalysts, for example inorganic or organic acids, such as hydrochloric acid, sulfuric acid, phosphoric acid, sulfonic acid, sulfamido acids or haloacetic acids. The condensation is preferably carried out solvent-free at 90 to 200 ° C, preferably at 100 to 160 ° C. In a further preferred embodiment, the reaction takes place in the presence of an organic solvent which forms an azeotrope with water, for example toluene, xylene, higher aromatics or mixtures thereof. The reaction mixture is heated to a temperature of 90 to 200 ° C, preferably 100 to 160 ° C, wherein the resulting reaction water is removed during the reaction by azeotropic distillation. Solvents that do not release protons under condensation conditions may remain in the products after the condensation reaction. The resins can be used directly or after neutralization of the catalyst, optionally after further dilution of the solution with aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, eg gasoline fractions, kerosene, decane, pentadecane, toluene, xylene, ethylbenzene or solvents such as ^® Solvent Naphtha, ^® Shellsol AB, ^® Solvesso 150, ^® Solvesso 200, ^® Exxsol, ^® ISOPAR and ^® Shellsol D types.

The proportions by weight of constituents A) and B) in the additives according to the invention can vary within wide limits, depending on the application. they lay preferably between 10 and 99.999% by weight of A), in particular between 20 and 99.995% by weight of A). The proportion of components B) is 0.005 to 20 wt .-%.

Surprisingly, it has also been found that a further increase in the effectiveness as a lubricant additive is achieved when the mixtures according to the invention are used together with nitrogen-containing paraffin dispersants. Paraffin dispersants are additives which reduce the size of the precipitated wax crystals as the oil cools and, moreover, cause the paraffin particles not to settle but to remain colloidally dispersed with significantly reduced sedimentation effort.

The paraffin dispersants are preferably low molecular weight or polymeric, oil-soluble compounds having ionic or polar groups, for example amine salts, imides and / or amides. Particularly preferred paraffin dispersants contain reaction products of secondary fatty amines having 8 to 36 carbon atoms, in particular dicoco fatty amine, ditallow fatty amine and distearylamine. Paraffin dispersants which have been obtained by reaction of aliphatic or aromatic amines, preferably long-chain aliphatic amines, with aliphatic or aromatic mono-, di-, tri- or tetracarboxylic acids or their anhydrides have proven particularly suitable (cf. US 4 211 534 ). Other paraffin dispersants are copolymers of maleic anhydride and α, β-unsaturated compounds, which can optionally be reacted with primary monoalkylamines and / or aliphatic alcohols (cf. EP-A-0 154 177 ), the reaction products of Alkenylspirobislactonen with amines (see. EP-A-0 413 279 B1) and after

EP-A-0 606 055 A2 Reaction products of terpolymers based on α, β-unsaturated dicarboxylic acid anhydrides, α, β-unsaturated compounds and polyoxyalkylene ethers of lower unsaturated alcohols.

Particularly preferred paraffin dispersants are prepared by reacting compounds containing an acyl group with an amine. This amine is a compound of the formula NR ⁶ R ⁷ R ⁸ , in which R ⁶ , R ⁷ and R ^{8 may be} identical or different, and at least one of these groups is C ₈ -C ₃₆ -alkyl, C ₆ - C ₃₆ -cycloalkyl, C ₈ -C ₃₆ -alkenyl, in particular C ₁₂ -C ₂₄ -alkyl, C ₁₂ -C ₂₄ -alkenyl or cyclohexyl, and the remaining groups are either hydrogen, C ₁ -C ₃₆ alkyl, C ₂ -C ₃₆ alkenyl, cyclohexyl, or a group of the formulas - (AO) _x -E or - (CH ₂ ) _n -NYZ where A is an ethylene or propylene group, x is a number from 1 to 50, E = H, C ₁ -C ₃₀ -alkyl, C ₅ -C ₁₂ -cycloalkyl or C ₆ -C ₃₀ -aryl, and n 2, 3 or 4, and Y and Z independently of one another are H, C ₁ -C ₃₀ -alkyl or - (AO) _x . By acyl group is meant here a functional group of the following formula:

> C = O

The paraffin dispersants can be added to the additives according to the invention or added separately to the middle distillate to be added. The amount ratio between paraffin dispersants and the additives according to the invention is between 5: 1 and 1: 5 and preferably between 3: 1 and 1: 3.

For the preparation of additive packages for specific problem solutions, the additives according to the invention can also be used together with one or more oil-soluble co-additives which in themselves improve the lubricity and / or the cold flow properties of crude oils, lubricating oils or fuel oils. Examples of such co-additives are vinyl acetate-containing copolymers or terpolymers of ethylene, comb polymers and oil-soluble amphiphiles.

For example, mixtures of the additives according to the invention with copolymers which have 10 to 40% by weight of vinyl acetate and 60 to 90% by weight of ethylene have proven outstanding. According to a further embodiment of the invention, the additives according to the invention are mixed with ethylene / vinyl acetate / vinyl 2-ethylhexanoate terpolymers, ethylene / vinyl acetate / vinyl neononanoate terpolymers and / or ethylene / vinyl acetate / vinyl neodecanoate terpolymers to simultaneously improve flowability and lubricity of mineral oils or mineral oil distillates. The terpolymers of vinyl 2-ethylhexanoate, vinyl neononanoate or vinyl neodecanoate contain, in addition to ethylene, 10 to 35% by weight of vinyl acetate and 1 to 25% by weight of the particular long-chain vinyl ester. Other preferred copolymers contain in addition to ethylene and 10 to 35 wt .-% vinyl esters or 0.5 to 20 wt .-% of olefin having 3 to 10 carbon atoms such. B. isobutylene, diisobutylene, 4-methylpentene or norbornene.

Finally, in a further embodiment of the invention, the additives according to the invention are used together with comb polymers. This term refers to polymers in which hydrocarbon radicals having at least 8, in particular at least 10, carbon atoms are bonded to a polymer backbone. Preferably, they are homopolymers whose alkyl side chains contain at least 8 and in particular at least 10 carbon atoms. In the case of copolymers, at least 20%, preferably at least 30% of the monomers have side chains (cf. Comb-like Polymers-Structure and Properties; NA Platé and VP Shibaev, J. Polym. Sci. Macromolecular Revs. 1974, 8, 117 ff ). Examples of suitable comb polymers are, for example, fumarate / vinyl acetate copolymers (cf. EP 0 153 176 A1 ), Copolymers of a C ₆ -C ₂₄ -α-olefin and a NC ₆ -C ₂₂ -alkylmaleimide (cf. EP-A-0 320 766 Further, esterified olefin / maleic anhydride copolymers, polymers and copolymers of α-olefins and esterified copolymers of styrene and maleic anhydride.

beschrieben werden. Darin bedeuten

A

R', COOR', OCOR', R"-COOR' oder OR';

D

H, CH₃, A oder R;

E

H oder A;

G

H, R", R"-COOR', einen Arylrest oder einen heterocyclischen Rest;

M

H, COOR", OCOR", OR" oder COOH;

N

H, R", COOR", OCOR, COOH oder einen Arylrest;

R'

eine Kohlenwasserstoffkette mit 8-150 Kohlenstoffatomen;

R"

eine Kohlenwasserstoffkette mit 1 bis 10 Kohlenstoffatomen;

m

eine Zahl zwischen 0,4 und 1,0; und

n

eine Zahl zwischen 0 und 0,6.

Comb polymers may, for example, be represented by the formula

to be discribed. Mean in it

A

R ', COOR', OCOR ', R "-COOR' or OR ';

D

H, CH _3, A or R;

e

H or A;

G

H, R ", R" -COOR ', an aryl radical or a heterocyclic radical;

M

H, COOR ", OCOR", OR "or COOH;

N

H, R ", COOR", OCOR, COOH or an aryl radical;

R '

a hydrocarbon chain of 8-150 carbon atoms;

R "

a hydrocarbon chain of 1 to 10 carbon atoms;

m

a number between 0.4 and 1.0; and

n

a number between 0 and 0.6.

The mixing ratio (in parts by weight) of the additives according to the invention with ethylene copolymers or comb polymers is in each case 1:10 to 20: 1, preferably 1: 1 to 10: 1.

The oily liquids of the invention are particularly suitable for use as fuel oil in diesel engines.

The oily liquids according to the invention are added to oils as additives in amounts of 0.02 to 10% by weight. They may be used as such or dissolved in solvents, such as aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures such as toluene, xylene, ethylbenzene, decane, pentadecane, gasoline fractions, diesel, kerosene or commercial solvent mixtures such as Solvent Naphtha, ^® Shellsol AB, ^® Solvesso 150, ^® Solvesso 200, ^® Exxsol, ^® Isopar and ^® Shellsol D types, as well as polar solvents such as alcohols, glycols and esters. Preferably, the additives of the invention contain up to 70%, especially 5 to 60%, in particular 10 to 40% by weight of solvent. With particular preference, they are used without the addition of further solvents.

The oily liquids of the invention can be stored at elevated temperature for a long time without aging effects, without causing aging phenomena such as resinification and the formation of insoluble structures or deposits in storage containers and / or engine parts. In addition, they improve the oxidation stability of the oils additized with them. This is particularly advantageous for oils containing larger amounts of cracking oils.

A further advantage of the oily liquids according to the invention is their crystallization temperature, which is lower than the fatty acid esters used according to the prior art as lubricity additives. So you can also with low temperatures of, for example, 0 ° C to -20 ° C and sometimes lower are used without problems.

The oily liquids according to the invention are particularly suitable as additives for use in middle distillates. As middle distillates are in particular those mineral oils which are obtained by distillation of crude oil and boil in the range of 120 to 450 ° C, for example kerosene, jet fuel, diesel and fuel oil. The oils may also contain or consist of alcohols such as methanol and / or ethanol. Preferably, the additives of the present invention are used in middle distillates containing less than 350 ppm sulfur, more preferably less than 200 ppm sulfur, and in special cases less than 50 ppm and less than 10 ppm sulfur, respectively. These are generally those middle distillates that have been subjected to a hydrogenating refining, and therefore contain only small amounts of polyaromatic and polar compounds that give them a natural lubricating effect. The additives according to the invention are furthermore preferably used in middle distillates which have 95% distillation points below 370.degree. C., in particular 350.degree. C. and in special cases below 330.degree. The same are the additives of the invention for use in synthetic fuels with also low lubricity, as z. B. in the Fischer-Tropsch process, suitable. The lubricity-enhanced oils have a wear scar diameter measured by the HFRR test of preferably less than 460 μm, especially less than 450 μm. The oily liquids according to the invention can also be used as components in lubricating oils.

The oily liquids may be used alone or together with other additives such as pour point depressants, corrosion inhibitors, antioxidants, sludge inhibitors, dehazers, conductivity improvers, lubricity additives, and cloud point depressant additives. Furthermore, they are successfully used together with additive packages containing, among others, known ashless dispersing additives, detergents, defoamers, antioxidants, dehazers, demulsifiers and corrosion inhibitors.

The advantages of the oily liquids of the invention are further illustrated by the following examples.

Examples

In the following, the constituents of the oily liquids are characterized.

Iodine numbers are determined by Kaufmann. For this purpose, the sample is mixed with a defined amount of a methanolic bromine solution, wherein an equivalent amount of bromine is added to the content of double bonds. The excess of bromine is back titrated with sodium thiosulfate. Table 1: Characterization of the fatty acid esters used example Chemical name Iodine number [gJ / 100g] A1 Rapsölsäuremethylester containing as main components 45% oleic acid, 39% linoleic acid, 4.5% linolenic acid 123 A2 Soybean oil methyl ester containing as main components 25% oleic acid, 51% linoleic acid, 7% linolenic acid 134 A3 Tallow fatty acid methyl ester containing as main components, 65% oleic acid, 18% linoleic acid 102 Characterization of the alkylphenol resins used B1 C ₂₀ -C ₂₄ -alkylphenol-formaldehyde resin prepared by condensing a mixture of C ₂₀ -C ₂₄ -alkylphenol with 35 mol% of di (C ₂₀ -C ₂₄ -alkyl) phenol, with formaldehyde, M w 2500 g / mol; 50% in solvent naphtha B2 Dodecylphenol-formaldehyde resin prepared by condensing a mixture of dodecylphenol with 1.3 mol% of didodecylphenol, with formaldehyde, Mw 2200 g / mol; 50% in solvent naphtha B3 Nonylphenolformaldehyde resin prepared by condensing a mixture of nonylphenol with 0.5 mol% dinonylphenol, with formaldehyde, Mw 2000 g / mol; 50% in solvent naphtha

Oxidation stability of the additives

10 g of the fatty acid mixture to be tested and the amount of resin indicated in Table 3 are weighed into a 500 ml Erlenmeyer flask. The flask is stored for three days at a temperature of 90 ° C in a drying oven, where daily the atmosphere above the additive is replaced by passing an air stream.

After conditioning, the mixture is allowed to cool for one hour at room temperature. Subsequently, 500 ml of diesel fuel (test oil 1) are added and thoroughly mixed. After two hours of use, the mixture is visually assessed for any precipitation, turbidity, insoluble matter, etc., giving evidence of oxidative changes (visual assessment). It is then filtered through a 0.8 micron filter at a pressure difference of 800 mbar. The total amount must be filterable within 2 minutes, otherwise the volume filtered after 2 minutes is noted. Table 3: oxidation stability example A B visual assessment filtration 1 (See) - - clear 34 s 2 (Cf.) 10 g A1 - cloudy + insoluble resin 120 s / 210 ml 3 (Cf.) 10 g A2 - cloudy + insoluble resin 120 s / 330 ml 4 (Cf.) 10 g A3 - cloudy + insoluble resin 120 s / 470 ml 5 10 g A1 0.5 g B3 homogeneously cloudy 79 s 6 10 g A1 1 g B3 almost clear 52 s 7 10 g A1 2g B3 clear 46 s 8th 10 g A1 0.5 g B1 clear 45 s 9 10 g A1 2 g B1 clear 43 s 10 10 g A1 1 g B2 clear 47 s 11 10 g A1 2g B2 clear 43 s 12 10 g A2 1g B1 clear 39 s 13 10 g A2 1g B3 clear 37 s 14 10 g A2 0.1 g B3 clear 42 s 15 10 g A3 1 g B3 clear 40 s na = not applicable, as not completely soluble

Lubricating effect in middle distillates

The lubricating effect of the additives was tested by means of an HFRR instrument from PCS Instruments on additized oils at 60 ° C. The High Frequency Reciprocating Rig Test (HFRR) is described in D. Wei, H. Spikes, Wear, Vol. 2, p. 217, 1986 , The results are given as coefficient of friction and Wear Scar (WS 1.4). A low Wear Scar and a low friction coefficient (Friction) show a good lubricating effect. Wear scar values of less than
460 microns are considered indicative of a sufficient lubricating effect, but in practice, values of less than 400 microns are sought. The dosing rates in Table 6 are based on the amount of dosed active ingredient. Table 4: Characterization of the used test oils Test oil 1 Test oil 2 distillation IBP [° C] 171 164 20% [° C] 218 214 90% [° C] 323 342 FBP [° C] 352 367 Cloud Point [° C] -8.2 -7.7 CFPP [° C] -12 -13 Density @ 15 ° C [g / cm ³ ] .8262 0.8293 Sulfur [ppm] 15 195 Characterization of the polar nitrogen-containing compounds used C1 Reaction product of a dodecenyl spirobislactone with a mixture of primary and secondary tallow fatty amine, 60% in Solvent Naphtha (prepared according to EP-A-0413279 ) C2 Reaction product of a terpolymer of a C14 / 16-α-olefin, maleic anhydride and allyl polyglycol with 2 equivalents of ditallow fatty amine, 50% in Solvent Naphtha (prepared according to EP-A-0606055 ) C3 Reaction product of phthalic anhydride and 2 equivalents of di (hydrogenated tallow fat) amine, 50% in solvent naphtha (prepared according to EP-A-0061894 ) C4 Reaction product of ethylenediaminetetraacetic acid with 4 equivalents of ditallow fatty amine to the amide ammonium salt (prepared according to EP-A-0398101 ) Wear Scar in test oil 1 example Dosing rate A Dosing rate B Dosing rate C Wear Scar Friction 16 (Cf.) - - - 575 0,329 17 0.2% A1 - - 537 0.260 18 0.5% A1 - - 498 0,205 19 0.75% A1 - - 423 0,180 20 1.0% A1 - - 373 0.171 21 (Cf.) - 0.025% B1 - 555 0.312 22 (See) - 0.05% B1 - 467 0.201 23 0.5% A1 0.05% B1 387 0,178 24 0.4% A1 0.02% B1 - 448 0.195 25 0.3% A1 0.03% B1 - 408 0,178 26 (Cf.) - 0.05% B3 - 565 0,320 27 (Cf.) - 0.1% B3 - 510 0.243 28 0.5% A1 0.05% B3 - 382 0,180 29 0.5% A1 0.1% B3 - 303 0.174 30 0.3% A1 0.075% B3 - 432 0,181 31 0.3% A2 - - 523 0,248 32 0.3% A2 0.03% B1 - 376 0.182 33 0.3% A2 0.03% B2 - 391 0.185 34 0.25% A2 0.02% B1 0.01% C1 371 0,178 35 0.25% A2 0.02% B1 0.01% C2 343 0.176 36 0.25% A2 0.02% B1 0.01% C3 365 0.177 37 0.25% A2 0.02% B1 0.01% C4 358 0,178 Wear Scar in test oil 2 example Dosing rate A Dosing rate B Dosing rate C Wear Scar Friction 38 (Cf.) - - - 540 0.266 39 (Cf.) 0.2% A2 - - 502 0.240 40 (Cf.) 0.4% A2 - - 435 0.207 41 (Cf.) 0.6% A2 - - 386 0.177 42 (Cf.) - 200 ppm B2 - 535 0,255 43 (Cf.) - 400 ppm B2 - 502 0,235 44 0.5% A2 200 ppm B2 - 275 0.166 45 0.4% A2 300 ppm B2 - 375 0.174 46 0.3% A2 150 ppm B2 100 ppm C1 398 0,187 47 0.25% A2 150 ppm B2 100 ppm C2 403 0.188

Claims (10)

1. The use of an oily liquid, comprising

   A) at least one ester of fatty acids whose carbon chain lengths are between 8 and 30 carbon atoms, and a monohydric C₁-C₅-alcohol, at least 50% of the fatty acid radicals containing at least one double bond, and

   B) from 0.005 to 20% by weight of at least one alkylphenol-aldehyde resin, obtainable by condensing

   (i) at least one alkylphenol having at least one C₆-C₂₄-alkyl or C₆-C₂₄-alkenyl radical and

   (ii) at least one aldehyde or ketone
   to a degree of condensation of between 2 and 50 alkylphenol units, in fuel oils having a maximum sulfur content of 0.035% by weight, in an amount of from 0.02 to 10% by weight, based on the fuel oil, for improving the oxidation stability of the fuel oils.
2. The use as claimed in claim 1, wherein the iodine number of constituent A) is more than 50 g of I/100 g of ester.
3. The use as claimed in one or more of claims 1 to 2, wherein the fatty acids which are a constituent of component A) contain from 10 to 26 carbon atoms.
4. The use as claimed in one or more of claims 1 to 3, wherein the fatty acid esters A) contain at least 75% by weight of fatty acids having one or more double bonds.
5. The use as claimed in one or more of claims 1 to 4, wherein the fatty acid mixtures contain one or more dicarboxylic acids.
6. The use as claimed in one or more of claims 1 to 5, wherein the alcohols from which constituent A) is derived are methanol or ethanol.
7. The use as claimed in one or more of claims 1 to 6, wherein constituent A) is derived from fatty acid mixtures which comprise up to 20% by weight of saturated fatty acids.
8. The use as claimed in one or more of claims 1 to 7, which also comprises at least one nitrogen-containing paraffin dispersant.
9. The use as claimed in one or more of claims 1 to 8, which also comprises at least one ethylene copolymer.
10. The use as claimed in one or more of claims 1 to 9, which also comprises at least one comb polymer.